study guide Flashcards
exam 2 (205 cards)
1
Q
prepares cell for replicating DNA; cell is busy doubling its contents in preparation for an eventual cell division
A
G1
2
Q
DNA replication
A
S
3
Q
prepares cell for segregation/division of genome and cytoplasma
A
G2
4
Q
chromosome segregation (mitosis) and separation of daughter cells (cytokinesis)
A
M
5
Q
after mitosis cells enter
A
G1 phase
6
Q
time between mitosis and G1 phase
A
R point
7
Q
R-point
A
cells require external signals, such as growth factors and hormones, to continue cell cycle progression
8
Q
R point occurs when?
A
a few hours before the onset of DNA synthesis
9
Q
when cells get to the R-point they make a decision as to whether they have enough nutrients to sustain them through DNA replications or they need to enter
A
G0 phase, the resting phase
10
Q
growth factors stimulate synthesis of
A
cyclins D and E
11
Q
Cyclin D partners with
A
cdk4 or cdk6
12
Q
Cyclin E partners with
A
cdk2
13
Q
99.9% of cell are in the _____
A
Go phase reason why it is so important to go through the R-point
14
Q
in nearly all cancers the
A
R- point is defective
15
Q
when enough of cyclin D/cdk4-6 and cyclin E/cdk2 complexes are activated, they
A
phosphorylate Rb protein
16
Q
normally the Rb protein is
A
hypophosphorylated
17
Q
when RB is hyposhorylated they complex with ______ needed for cell proliferation and ______ them from binding to DNA
A
when Rb is hypophosporylated they complex with transcription factors needed for cell proliferation and prevents them from binding to DNA
18
Q
phosphorylation by the cyclin D/cdk4-6 and cyclin E/cdk2 complexes causes a
A
conformational change that releases the TFs
19
Q
what do the TFs bind once acted by the cyclins?
A
bind to DNA and activate transcription that encodes proteins which push cells through R-point and S-phase
20
Q
once DNA synthesis commences, a _______ is activated that destroys the cyclin D/cdk4-6 and cyclin E/cdk2 , thus _________ the complex
A
once DNA synthesis commences, a protease is activated that destroys the cyclin D/cdk4-6 and cyclin E/cdk2 , thus inactivating the complex
21
Q
new cancer chemotherapies are now in use and in clinical trials that
A
block Cdk2 and Cdk4 function
22
Q
MFP
A
cylin B/cdk1
23
Q
consequences of MFP activation (2)
A
(1) phosphorylation of lamins, leading to nuclear membrane disassembly
(2) phosphorylation of histones, initiating chromatin condensation
24
Q
altered proliferative states of cells that are reversible/stoppable: proliferation stops when the stimulus that provoked it is removed (4)
A
(1) regeneration
(2) hyperplesia
(3) metaplasia
(4) dysplasia
25
irreversible proliferation: proliferation continues in the absence of an external stimulus
neoplasia
26
1-for-1 replacement of lost cells by the same cell type
regeneration
27
endothelial cell ________ following vascular surgery or liver-cell _______ following partial hepatectomy or live-donor liver transplants
regeneration
28
hyperplasia
increase in the number of cells in a tissue; cells are truly differentiated. Can be helpful or hramful
29
metaplasia
adaptive substitution of one cell type for another
30
dysplasia
activated metabolic pathways for proliferation; loss of orientation in a tissue
31
neoplasia (2)
- benign
| - malignant
32
benign
loss of proliferation control only
33
example of a benign tumor
fibroids
34
malignant
loss of both proliferation and positional controls
35
example of malignant
metastatic tumors in cancer
36
hyperplaisa: helpful or harmful
hematopoietic cells in bone marrow following severe blood loss or changes in altitude
helpful
37
hyperplaisa: helpful or harmful
thyroid cells in Graves diseases
harmful
38
hyperplaisa: helpful or harmful
smooth muscle cells in the arterial wall in atherosclerosis or following vascular surgery. What is this?
harmful and it is called restenosis
39
replacement of ciliated columnar epithelium by stratified squamous epithelium in response to chronic inflammation
metaplasia
40
abnormal appearance of cells such as pleiotropy, disorientation within tissue and high mitotic rate is indicative of
dysplasia
41
cervical ______as seen in on a Pap smear in women and _______ moles removed from skin
dysplasia
42
the position of a cell within a tissue can determine its
proliferation rate
43
why does the position within a cell determine proliferation rate?
information in the extracellular matrix helps regulate cell proliferation
44
Why have apoptosis?
you need a balance between cell death and cell proliferation
45
leads to inflammation
necrosis
46
leads to phagocytosis
apoptosis
47
How is necrosis triggered?
by sustained ischemia, physical or chemical trauma
48
How is apoptosis triggered?
by specific signals that activate specific genes
49
What happens at the start of necrosis?
Cells swell, organelles damaged, chromatin randomly degraded
50
What happens to cells and organelles in necrosis?
cells lyse and organelles destroyed
51
What happens at the start of apoptosis?
cells shrink, organelles intact, chromatin degraded systematically
52
What happens to cells and organelles in apoptosis?
membrane blebs, cell contents retained
53
the three basic steps of apoptosis
(1) induction
(2) modulation
(3) execution
54
Inducers of apoptosis (3)
(1) physiological activators
(2) Damage-related activators
(3) therapy-associated
55
physiological activators
TNF-alpha,
FasL,
growth/ survival factor withdrawal,
glucocorticoids
56
Damage-related activators
```
viral infection,
heat schock,
toxins,
tumor suppressors,
oxidants/free radicals
```
57
Therapy-associated
UV/gamma radiation
| chemotherapeutic drugs
58
"death signals"
inducers
59
"death effectors"
effectors
60
effectors
caspases
| endonucleases
61
mitochondrial pathway
intrinsic
62
death-receptor- initiated pathway
extrinsic
63
what happens if we go through the intrinsic pathway?
the process may be modulated (either enhanced or dampened) by members of the Bcl family
64
modulators
Bcl-2 family
65
key feature of the intrinsic pathway
mitochondrial leakage of cytochrome C activating the caspase cascade
66
key feature of te extrinsic pathway
death receptors activating the caspase cascade
67
How is the intrinsic pathway activated?
by growth factors/survival factor withdrawal, glucocorticoids, viruses, DNA damage-causing events, toxins, oxidized compounds and ischemia
68
How is the extrinsic pathway activated?
by TNF-alpha or Fas ligand binding to their receptors on the cell surface
69
the intrinsic pathway works by creating ______ through the ______ membrane tat cause ________ leakage into the cytoplasm that initiates the ______ cascade
The intrinsic pathway works by creating channels through the mitochondrial membrane that cause cytochrome C leakage into the cytoplasm that initiates the caspase cascade
70
in the extrinsic pathway, the cytoplasmic tail of the ______ or _________ receptor directly initiates the _____ cascade when the _________________.
in the extrinsic pathway, the cytoplasmic tail of the TNF-alpha or FasL receptor directly initiates the caspase cascade when the receptor is occupied by its ligand
71
Both extrinsic and intrinsic, result in massive amounts of ________ activity
caspase 3
72
Caspase-3
chief executioner of the cell in both extrinsic and intrinsic pathways for apoptosis
73
The caspases activate specific ________ that cleave DNA in the linker regions between the _____ and also cleave ______ proteins resulting in the formation blebs
The caspases activate specific endonucleases that cleave DNA in the linker regions between the nucleosomes and also cleave cytoskeletal proteins resulting in the formation of blebs
74
the blebs formed by the pathway apoptosis are
taken in via phagocytosis
75
inhibitors of apoptosis might be useful in limiting the damage caused by
strokes and heart attacks
76
goal of therapeutic solution with apoptosis in cancer and restenosis
increase apoptosis of the tumor cells or hyper-proliferating smooth muscles
77
goal of therapeutic solution with apoptosis in Hashimoto
decrease apoptosis in the thyroid cells
78
Major ECM molecules (8)
(1) collagens
(2) elastin
(3) proteoglycans
(4) Matricellular proteins
(5) integrins
(6) Matrix metalloproteinases
(7) cell adhesion molecules
(8) cadherins
79
provide structural integrity for bone and cartilage and major component of the Basement membrane
collagens
80
Collagen Type I found
almost everywhere
81
Collagen type II found
almost exclusively in cartilage
82
Collagen type IV found and role
best remembered for its role in basement membranes (basal lamina)
83
Type I and II are
fibril forming collagens
84
Type IV is a
network (sheet) forming collagen.
-think lamina
85
Type I is like a
CT collagen
86
Type II is like a
cartilage collagen
87
Type IV is like the
epithelial basement membrane/basal lamina collagen
88
Type XVIII is important because
it is blood vessel-specific and contains an internal peptide sequence
89
endostatin is cleaved by an ______ from ______
endostatin is cleaved by an MMP from Collagen XVIII
90
What is endostatin?
powerful anti-angiogenesis protein
91
Elastin is cross-linked with
fibrillin
92
elastin
major component of the elastic laminae of large artery wall
93
Proteoglycans and Hyaluronan are _______ and provide ______ and ______ for cells and cartilage
Proteoglycans and Hyaluronan are ubiquitous and provide hydration and structural support for cells and cartilage
94
acts as reservoirs for growth factors and cytokines
Proteoglycans and Hyaluronan
95
Shock-absorber
Proteoglycans and Hyaluronan
96
Matricellular proteins
secreted and bind tightly to the cell surface through their interactions with integrins
97
Matricellular protein examples (2)
(1) fibronectin
| (2) lamina
98
help attach cells to each other and to the ECM via multiple binding sites for cells, proteoglycans, and collagen
Matricellular proeins
99
found in CT/mesenchymal matrices
fibronectin
100
found in basement membranes
laminin
101
A relative nwcomer in the matricellular protein field are the ______
CCN family of proteins
102
Matricellular proteins are connected to the cytoskeleton and signaling pathways via their interactions with _____ and _______ and thus help regulate important cell functions like ______, _______ and _______
via their interactions with integrins and growth factors and thus help regulate important cell functions like proliferation, motility and differentiation
103
receptors for fibronectin, laminins, CCN proteins as well as other molecules
Integrins
104
Integrins often connect to ___________ and ________ machinery via tightly complexed proteins on ________ side of membranes
Integrins often connected to cell signaling and cytoskeletal machinery via tightly complexed proteins on cytoplasmic side of membranes
105
Cadherins are _____-requiring cell adhesion molecules important in maintaining tissue _____ by connecting the _______ of adjacent cells.
Cadherins are calcium-requiring cell adhesion molecules important in maintaining tissue integrity by connecting the desmosomes of adjacent cells
106
Defects in cadherins cause
blistering
107
also critical in embryonic development; required for compaction of the embryo
cadherins
108
ICAM-1
1st cell adhesion molecules discovered
109
P-selectin
matricellular protein
110
_______ "rolling" along the vascular endothelium is due to weak ________ interactions between _____ on the endothelial cell and a ______ ligand on the _______
Leukocyte "rolling" along the vascular endothelium is due to weak on-off interactions between P-selectin on the endothelial cell and a carbohydrate ligand on the leukocyte.
111
If a tissue is inflamed, the ECs in that area express ___________, which binds to the _____ receptor on the leukocyte. This activates a specific _____ that binds tightly to ______ on the EC membrane, causing the leukocyte to _____. This initiates __________ of the _____.
If a tissue is inflamed, the ECs in that area express Platelet Activating Factor, which binds to the PAF receptor on the leukocyte. This activates a specific integrin that binds tightly to ICAM-1 on the EC membrane, causing the leukocyte to stick. This initiates extravasation of the leukocyte
112
This initiates extravasation of the leukocyte
migration between EC to enter the inflamed area
113
MMPs
metal-requiring enzymes
114
MMPs degrade
matrix molecules including collagens, proteoglycans and other proteins
115
MMPs are required for
- cancer cell metastasis
- tissue remodeling
- wound healing
- angiogenesis
116
a major structural protein that is present in the elastic laminae in the wall of large arteries
elastin
117
elastin
long, rod-like protein which is cross-linked
118
cross-links in elastin mediated by
fibrillin
119
defective fibrillin leads to
stretching of the artery--> aneurysm
120
Axis in women
HPO
121
Axis in men
HPT
122
Gonadotropin releasing hormone:
source
hypothalamus (brain)
123
Gonadotropin releasing hormone:
target
anterior pituitary
124
Gonadotropin releasing hormone:
action
synthesis and secretion of FSH and LH
125
Follicle Stimulating Hormone:
source
anterior pituitary
126
Follicle Stimulating Hormone:
target
ovary
127
Follicle Stimulating Hormone:
action
stimulates ovarian follicle growth, differentiation and steroidogenesis
128
Luteinizing hormone:
source
anterior pituitary
129
Luteinizing hormone:
target
ovary
130
Luteinizing hormone:
action
stimulates ovulation, corpus luteum formation and steroidogenesis
131
Estrogens:
source
ovary; follicle cells
132
Estrogens:
target
uterus, vagina oviduct, mammary glands
133
Estrogens:
action
growth and differentiation of targets
134
Progestins:
source
corpus luteum
135
progestins:
target
uterus, vagina, oviduct, mammary glands
136
Progestins:
action
growth and differentiation of targets
137
1/? couples experience fertility issues
1/8
138
Males major cause of infertility (4)
(1) varicocele
(2) sperm motility problems
(3) hormonal imbalances in HPT axis
(4) congenital absence of the vas deference
139
Females major cause of infertility (4)
(1) PCOS
(2) hormonal imbalances in the HPO
(3) insufficient progesterone production
(4) anatomic problems like Asherman syndrome
140
PCOS
not enough FSH
141
Asherman syndrome
scarring from either surgeries, fibroids, endometriosis...
142
when oocytes are fertilized what is the arrested state?
metaphase of meiosis II
143
once fertilization happens what happens?
oocyte goes through the rest of Meiosis II and in an hour the zygote will have two pronucli
144
why does the pronucli have two eggs?
one from the oocyte and the other from the sperm
145
The pronuclei fuse and go through a round of _____ to double the number of chromosomes, and then undergo the first ________ which is a mitotic division that produces ____ equal daughter cells each with a full complement of chromosomes
The pronuclei fuse and go through a round of DNA replication to double the number of chromosomes, and then undergo the first zygotic cleavage which is a mitotic division that produces 2 equal daughter cells each with a full complement of chromosomes
146
to produce ___ diploid blastomeres it has to have the ____ DNA/chromosome content before it divides
to produce 2 diploid blastomeres it has to have the 4n DNA/chromosome content before it divides
147
how long does it take for a fertilized egg to go through the first cleavage
24-30hr
148
after 3 days of fertilization how many cells should there be?
8
149
blastomeres
cells are identical
150
can 2 of the 8 of the blastomerse can be plucked up for genetic diagnosis
YES!
151
what is the current best method for PGD uses
trophoblast cells from an early (day 5 or 6) blastocyst
152
The ______ is formed around Day 3-4 by a _________ called compaction and it is the first time that we see _____ (differences between cells) in the embryo
The morula is formed around Day 3-4 by a cadherin-dependent process called compaction and it is the first time that we see polarity (differences between cells) in the embryo
153
until when the zona pellucida remains around the embryo
until the early blastocyst stage
154
fluid expansion of the blastocoel puts enough hydrodynamic pressure on the zona pellucida to break it open and allow blastocyst hatching
ZP shedding
155
the blastocyst consist of (3)
(1) inner cell mass
(2) trohoblasts
(3) blastocoel
156
fluid-filled space
blastocoel
157
will give rise to the placenta
trophoblasts
158
will give rise to the embryo and is the best source of stem cells
inner cell mass
159
where does the blastocyst implant?
uterine wall
160
represents the first real 3-D embryonic structure
gastrulation
161
rise from the epiblast
germ layers
162
germ layers present at which stage
gastrulation
163
contains the epiblast and hypoblasts
blastocyst
164
gastrulation occurs after
blastocyst formation
165
all the embryonic cells and critical structures and systems are pretty much in place by the end of
week 8
166
high spontaneous abortion rate (3)
(1) major chromosmal abnormalities
(2) early cleavage problems
(3) progesterone insufficiency
167
where does fertilization occurs?
fallopian tube
168
supports the first 20 weeks of gestation by secreting progesterone that helps maintain a functional endometrial layer in the uterus
corpus luteum
169
what keeps the corpus luteum in top progesterone-secreting shape
LH and later hCG
170
Sperm transport
mostly propelled by contraction of uterine smooth muscle cells and ciliary
171
critical to fertility because it enable sperm to swim well and prepares them for acrosome rxn. if it does not go well sperm is useless and infertility results
capacitation
172
how is capacitation mimicked in IVF clinic?
washing the sperm before IUI or IVF
173
When the sperm come into contact with the follicular cells surroundings the oocyte the _____ membrane perforates and realeases enzymes that can chew up the matrix and ______ thus allowing sperm to penetrate the ZP and fuse with the ___________
When the sperm come into contact with the follicular cells surroundings the oocyte the acrsome membrane perforates and realeases enzymes that can chew up the matrix and Zona pellucida thus allowing sperm to penetrate the ZP and fuse with the oocyte plasma membrane
174
polyspermy leads to
triploid embryos... lethal
175
provides the block of polyspermy
cortical rxn
176
Fusion of the sperm and oocyte plasma membrane causes _____ pulses in the oocyte and triggers the ____ granules to exocytose their contents,which are enzymes that cross-link the proteins in the _____ preventing any additional sperm penetration
Fusion of the sperm and oocyte plasma membrane causes calcium pulses in the oocyte and triggers the corticol granules to exocytose their contents, which are enzymes that cross-link the proteins in the Zona pellucida preventing any additional sperm penetration
177
Ejaculation is followed by rapid ____, then comes the _______ rxn, followed by fusion of the sperm and oocytes, which initiates the ______ reaction via waves of ________ pulses across the cell
Ejaculation is followed by rapid capacitation, then comes the acrosome rxn, followed by fusion of the sperm and oocytes, which initiates the cortical reaction via waves of calcium pulses across the cell
178
age-dependent loss of oocytes
oocyte atreasia
179
absence of viable oocytes that can mature into secondary oocytes capable of being ovulated causes the onset of
menopause/fertility
180
did teratogenic drugs like thalidomide and diseases like Rubella have allowed embryologists to determine the precise timing of developmental events in humans?
Yes!!
181
when are complete gametes produced in males?
from puberty until death
182
in females the vast majority of oocytes in the ovary are arrested
prophase of Meiosis 1
183
gametes are ____ in chromosome number
haploid
184
gametes are
germ cells
185
in meiosis the parent cell is ____ and the progeny are ____
parent is diploid and progeny haploid
186
parent and progeny cells are genetically
different
187
liver, vascular enodothelium after surgery
regeneration
188
graves, restenosiss
hyperplasia
189
CPID smokers
Metaplasia
190
cervix, precursor to cancer
dysplasia
191
tissue/organs that are enlarging then it mush have more
proliferation than apoptosis
192
tissue/organs that are shrinking then it mush have more
apoptosis than proliferation
193
express the Fas receptor
lymphocytes
194
express the Fas ligand
endothelial cell
195
rolling
P-selectin- matricellular protein
196
Day:
| pronuclei fuse- fertilization
0
197
Day:
2-cell embryo/first embryonic cleavage
1
198
Day:
4-cell mebryon
2
199
Day:
8 cell embryo/embryo biopsy stage
2.5-3
200
Morula- compaction/first differentiated cells
3-4
201
Day:
| Blastocyst- implantation period/embryo biopsy day 5-6
4-14
202
Day:
Gastrula/3 germ layers form from epiblast
15-17
203
invovled in contraction of thecal cells to expel the oocyte
PGE2
204
blocks activation of both T-cells and Natural Killer cells so that the mother does not immunologically reject an embryo or fetus
PGE2
205
stimulates the contraction of uterine myometrial smooth muscle cells during labor
PGE2
